Simnia Hiscocki
Total Page：16
File Type：pdf, Size：1020Kb
Molluscan Research 31(3): 167–175 ISSN 1323-5818 http://www.mapress.com/mr/ Magnolia Press A new species of Simnia from England (Caenogastropoda: Ovulidae) FELIX LORENZ1* & CHRISTIAN MELAUN2 1 Chiapponi-Lorenz Seashell Foundation (CLSF), Via Aspromonte 22, 23900 Lecco, Italy. 2 Biodiversity and Climate Research Centre (BiK-F), Medical Biodiversity and Parasitology, Senckenberganlage 25, 60325 Frankfurt am Main, Germany. *Corresponding author—Email: [email protected] Abstract A new species of Ovulidae, Simnia hiscocki, is described from the Cornwall Peninsula, England, and compared with Simnia patula occurring in the same area, from which it differs in shell- and radula-morphological features as well as ecological fea- tures. DNA analysis suggests that it is a very young species whose host-specificity to Eunicella verrucosa makes it a poten- tially useful species for monitoring sea-temperature-change. Key words: Ovulidae, Simnia, new sister species, Plymouth, radula differences, host-specific, climate change Introduction parallel to the shell's axis respectively), the relation between the distance between the bulge of the columella and the outer The family Ovulidae comprises more than 200 species side as opposed to the greatest dimension of the bulge (c) and distributed widely across tropical and sub-tropical seas the distance from the columellar bulge the to the outer lip (a) (Lorenz and Fehse 2009). Simnia patula (Pennant, 1777) is was examined (Fig. 1). an exception in this mainly tropical family, as it inhabits the Genomic DNA was isolated from tissue samples cold waters of the northern Atlantic along the coasts of (mantle or foot fragments) of five specimens of the species England and Norway. Only very recently, a sympatric sister- described here, and five specimens of Simnia patula by species was discovered on several sites along the Cornwall proteinase-K digestion and standard phenol-chloroform Peninsula and the Isles of Scilly, south-western England. It is extraction. We amplified the barcode region of the COI gene described below. using primers LCO1490 and HCO2198 (Folmer et al. 1994). PCR conditions were 94°C-50°C-72°C, 1 minute each for 40 cycles. Obtained PCR products were sequenced on a ABI Material and methods 3730 DNA Analyzer and the sequences analyzed using BioEdit (Hall 1999) and MEGA 4 (Tamura et al. 2007); this Thirty four live-collected specimens of Simnia hiscocki n. sp. and more than 30 specimens of Simnia patula were available resulted in fragment lengths of 658 bp. from several collecting sites around Plymouth, on the south Abbreviations of the Cornwall Peninsula, southwestern coast of England. Further specimens of Simnia patula were examined NHMUK: Natural History Museum, London CLSF: Chiapponi-Lorenz Seashell Foundation, Lecco from the northern coast of Brittany (MNHN, not registered), MNHN: Museum National d'Histoire Naturelle, Paris Guernsey, Orkney, from the Brittany in France (MNHN IM- 2008-2728, IM-2008-2729) and Lista Fyr in the south of Norway (all CLSF). The samples from the locations near Plymouth and Scilly were collected by diving and preserved Systematics in alcohol immediately after collecting. That allowed a Family Ovulidae superficial study of the anatomy and determination of sex in A recent review of this family is given by Lorenz and Fehse, most specimens. For the study of radulae, the animals were 2009. Members of the family occur in tropical and temperate softened in distilled water for one hour, removed from the seas, even at greater depths. Most species are associated with shell and then dissected. Radulae were compared from eight soft corals, leather corals and black corals which serve as specimens each of S. hiscocki and S. patula from Hand host. Some species feed also on sponges, brittle stars and Deeps. They were examined with standard light-microscopy, crinoids. The shell is mostly smooth or with fine striae photographed and drawn. without exposed posterior end and columellar teeth. The Because of the fragility of the shells, only the length labrum may have denticles and crenulations, as well as small was measured manually using a precision caliper, other spines occasionally. The mantle covers the shell and serves shell-parameters were taken from photographs of each shell. as camouflage by imitating parts of the host. The radular These photographs were taken with the aperture pointing up morphology is characteristic of the family. Development and the shell's axis parallel to the camera-lens. In addition to occurs through a veliger stage which can last for several the length and the greatest width (measured in right-angle or weeks before reaching the crawling stage. COPYRIGHT © 2011 MALACOLOGICAL SOCIETY OF AUSTRALASIA & SOCIETY FOR THE STUDY OF MOLLUSCAN DIVERSITY 167 168 LORENZ & MELAUN (2011) MOLLUSCAN RESEARCH, VOL. 31 Genus Simnia Risso, 1826 Additional material examined Type species: Simnia nicaeensis Risso, A. 1826. By subsequent Twenty-one further specimens in the collection of the designation). CLSF have been examined, measuring 9.4 to 18.7 mm in length (see Table 1). Members of this genus are distributed in the Atlantic and No specimens of S. hiscocki were found in the reference Mediterranean. All species of Simnia are characterized by a collection of the MNHN and from our research, it has very thin, fusiform shell which lacks a callosed labral margin apparently never been mentioned or illustrated, either alive and the columellar side displays very few callosities. or as empty shell, except for the reference given in the synonymy. Simnia hiscocki n. sp. Description Synonymy: Shell (Figs 2 & 4) (description based on holotype): Simnia cf. patula:- Lorenz and Fehse 2009, 97, pl. 123, Figs 9-10, Fragile, semi-transparent, narrow cylindrical. Posterior A212, A214. tapering, forming constricted, slightly twisted canal that widens very slightly along outer edge. Slight development of Material examined Type material callosity along peculiarly twisted funicular region, no funiculum visible. Columellar bulge faintly striate, not showing any callosity. Anterior tip pointed, formed by long, Holotype: 16.4 mm, Hand Deeps, Plymouth area, England (50°12.53’N 4°20.58’W), at 21 m depth on Eunicella well-developed and slightly calloused fossular fold. Labral edge very thin and fragile, no indication of callosity. Last verrucosa, MNHN 23297; Paratype 1: 16.8 mm, Hand whorl glossy and smooth, showing fine, regular longitudinal Deeps, Plymouth area, same data as holotype, CLSF 1-3609; Paratype 2: 13.3 mm, Hand Deeps, Plymouth area, same data growth-lines. Faint, distant incised striae visible on terminal collars and especially above the slightly callosed funicular as holotype, NHMUK 20110196; London; Paratype 3: 16.9 region. Overall colour of shell rich orange-cream, calloused mm, Hand Deeps, Plymouth area, same data as holotype, CLSF 1-3610; Paratype 4: 12.3 mm, Hatt Rock, Plymouth along posterior canal and fossular region slightly paler. Comparison with paratypes indicates no discernible area, (50°10.42’N 4°29.19’W), at 22 m depth, MNHN differences between smaller (young) shells and adults, 24242; Paratype 5: 14.2 mm, Hand Deeps, Plymouth area, same data as holotype, in private collection of Dirk Fehse, except smaller shells tend to have more distinct striae towards extremities. Only length of posterior canal varies Berlin; Paratype 6: 17.2 mm, Hilsea Point, Plymouth area, slightly, but shape and general colour constant. No (50°17.32’N 4°02.70’W), MNHN 24245. differences in shell-size between males and females (8 males, and 11 females). Shell dimensions – see Table 1. TABLE 1.Shell dimensions (in mm) of Simnia hiscocki n. sp. c = columella, a = aperture w = width, l = length (c)w/l = width/length, a/c = aperture/columella. lwcaw/la/c Holotype 16.4 6.3 13 8 38 62 Paratypes 14.3 5.2 10.7 7.0 36.7 65.6 (SD) (2.9) (1.0) (2.1) (1.6) (2.7) (10.9) Additional 12.0 4.3 8.9 5.4 31.0 52.5 specimens (4.3) (1.3) (2.7) (1.9) (8.3) (16.3) (SD) Head-foot (living material) (Figs 10A, B & C): Mantle thick, transparent with sparse wart-like papillae which vary in length. Some animals showing two or three small branches encircling pointed tip of papillae. In fully extended animal mantle forms regular corrugations along anterior part of labral edge. Siphon short, transparent and thick, foot fleshy and less transparent. Tentacles thick and short, usually not visible in photographs of active animal, mantle and foot decorated with conspicuous red transverse, parallel lines, FIGURE 1. A shell of Simnia sp. showing the parameters used in often with intermittent rows of discrete red spots. In some measurements; c = columella, a = aperture. specimens mantle covered only with rows of these spots; background coloration varies from brown to pale lemon. A NEW OVULID SPECIES FROM ENGLAND 169 Colour of proboscis greyish white. When withdrawn into than inner, with comb of 60-75 filaments, many bifurcate at shell, animal (visible through shell) appears bright red. tip. Radula (Fig. 9B): Typical of family, with flat rachidian Spawn: Of 15–20 circular egg-capsules 2.2–2.5 mm in tooth with pronounced central cusp and three to four diameter embedded in mucus to which mud and other denticles on either side. Lateral tooth with similar large particles may adhere. Capsules deposited around branches of central cusp and three to four smaller denticles. Inner host. Each capsule contains several hundred larvae. When marginal tooth flat, considerably enlarged, with 40–50 fine deposited, spawn pale yellow, and later turns brown due to filaments, some bifurcate at tip. Outer marginal tooth wider development of larval shells. FIGURE 2 Simnia hiscocki. A, dorsal, basal and lateral aspects of holotype (MNHN 23297); B, dorsal and basal aspect of paratype 1 (CLSF 1- 3609); C, dorsal and basal aspects of paratype 6 (MNHN 24245); D, basal aspect of paratype 4 (MNHN 24242); E, basal aspect of juvenile specimen (CLSF 1-3622); F, dorsal and basal aspects of paratype 2 (NHMUK 20110196).